Ipswich Mills Dam

Ipswich Mills Dam from Riverwalk footbridge

Tributary: Ipswich River

Approach: Dam Removal (in feasibility phase)

The Dam

The Ipswich Mills Dam is owned by the Town of Ipswich and is located on the Ipswich River in downtown Ipswich. The dam is the first from the sea, built on a natural rock outcrop (the “upper falls”) at the head of tide 3.7 miles from the river mouth. The interface between salt and fresh water is an extremely rare and productive ecosystem and the presence of the dam at the head of tide is especially detrimental. The dam is constructed of granite blocks and has an overall length of 200 ft, with a 120 ft long overflow spillway. It was constructed to power adjacent mills and currently has no functional use. A Denil fishpass was installed in 1995, but does not allow all fish species to pass such as rainbow smelt and American shad which do not swim up the ladder.

The Project

The Town of Ipswich recognizes the long-term maintenance, liability and environmental costs associated with the dam. In 2010, the Ipswich Board of Selectmen voted unanimously to begin exploring the environmental, technical, logistical and economic factors surrounding the removal of the Ipswich Mills Dam. A preliminary dam removal feasibility study was completed in 2014 which included analysis of three important factors that could influence the decision to maintain or remove the dam. The Town will be undertaking a more complete, follow-up study beginning in 2015 with the help of a federal Hurricane Sandy Coastal Resiliency Grant and funds from the MA Division of Ecological Restoration.